Ever felt that your laptop or smartphone battery drains too quickly? As the computational demands of software keep rising, they draw on a lot more memory and processing power, causing the hardware supporting them to consume more energy and generate more heat.
“This critical problem limits the performance and efficiency of electronic devices,” said A*STAR Institute of Materials Research and Engineering (A*STAR IMRE) Principal Scientist Anjan Soumyanarayanan.
Together with collaborators from the National University of Singapore, Soumyanarayanan and A*STAR IMRE colleagues are turning to a growing research field known as spintronics to develop faster, cleaner and cooler devices.
A key component of spintronics is the magnetic tunnel junction (MTJ), which consists of two magnetic layers separated by a thin insulator. The alignment of the magnetic layers changes the flow of electric current through the insulator: more current if they’re pointed in the same direction, less if they’re opposed. By switching between these two states, spintronic devices can store and process information in the binary of 0s and 1s used by almost all computers today, but more efficiently than conventional electronics.
However, speed limits and high switching energy costs remain a challenge for spintronics hoping to support future computing applications. To improve their switching efficiency, the researchers introduced skyrmions—nanometre-sized magnetic whirlpools—into an MTJ’s active magnetic layer. They combined standard MTJ materials with special chiral materials, developing a wafer-scale MTJ that can not only stably host a single skyrmion, but control it entirely with electricity.
“By combining two active layers to carefully tailor its magnetic properties, our skyrmionic MTJ stack can support all required computing operations at room temperature,” said Soumyanarayanan. “As the device can maintain multiple distinct states rather than just two, it can effectively store more information in the same physical space, supporting even more powerful computing.”
Compared to state-of-the-art spintronic memory devices, the team’s skyrmion-enhanced device offered faster switching speeds, yet used 1,000 times less energy. Soumyanarayanan credited this unprecedented energy efficiency to a unique switching mechanism that the researchers developed, where the applied electricity gently reshapes skyrmion stability rather than affecting a brute-force change of states.
Given their potential to facilitate new forms of computing, skyrmions could bring next-generation artificial intelligence (AI) technologies into everyday use. “Skyrmions have unique properties that can enable efficient unconventional computing. If successfully developed, this can enable AI processing directly on personal devices with minimal power consumption,” said Soumyanarayanan.
The team also ensured that their skyrmionic MTJ can be produced using industry-standard 200 mm silicon wafers and established manufacturing methods. “Rather than requiring entirely new fabrication methods, skyrmionic MTJs can be integrated into current production lines, accelerating their path to commercial adoption,” Soumyanarayanan added.
The A*STAR-affiliated researchers contributing to this research are from the A*STAR Institute of Materials Research and Engineering (A*STAR IMRE).
